According to the Academy of Nutrition and Dietetics, vegetarian, including vegan, diets typically meet or exceed recommended protein intakes, when caloric intakes are adequate. Moreover, there is no need to “combine” proteins, because protein from a variety of plant foods, eaten during the course of a day, supplies enough of all indispensable (essential) amino acids when caloric requirements are met.
In Vegan for Life, Jack Norris and Virginia Messina recommend a slightly higher protein intake for vegans (0.9 g/kg/d), because plant proteins aren’t digested as well as animal proteins. This may be less of an issue for people who consume more tofu and veggie meats made from processed soy protein but is more important for people who mainly consume legumes, nuts, and grains for protein.
Older adults need more protein to make up for age-related changes in protein metabolism and to offset inflammatory and catabolic conditions associated with chronic and acute diseases that occur commonly with aging. The recommendation for people over 60 years old is 1.0 to 1.3g/kg of protein per day.
It is easy to get enough protein on a vegan diet if you eat multiple servings of high-lysine foods (legumes, seitan, amaranth, quinoa, pistachios, and pumpkin seeds) each day. Legumes include soybeans and their products (tempeh, tofu, soy milk, soy meats, etc.), beans (garbanzo, kidney, pinto, etc.) and their products (falafel, hummus, refried, etc.), peas (green, split, black-eyed, etc.), lentils, and peanuts.
To ensure adequate protein status, vegans should eat 3–4 servings per day of the following foods which are both high in protein and the amino acid lysine: